18 July 2005

Shark Skin Sloop

by Kate Melville

The growth of marine organisms such as barnacles on ship hulls is a major drag for the naval industry, since their presence is one cause of increased energy costs. Researchers, led by Ralph Liedert at the University of Applied Sciences in Bremen, claim that they have solved this problem by using artificial shark skin, as its unique properties offer a structural design that prevents this so-called 'bio-fouling'. Liedert claims that covering ship hulls with artificial shark skin could help ships sail more smoothly with greater efficiency.

Shark skin comprises scales that can flex individually from each other, making it extremely difficult for organisms to adhere themselves to sharks. Liedert has produced a synthetic shark skin of elastic silicone, complete with the same significantly decreased contact surface. This reduced contact surface makes it harder for barnacles to attach, and reduces fouling by 67 percent. When applied to the ship hull, the artificial surface would enable ships to 'self-clean', and a speed of 4-5 knots would remove all organisms attached.

It has been known for some time that barnacles, mussels and algae cause up to a 15 percent increase in the drag resistance of ships, which drives up fuel bills and hampers a ship's performance. Until recently, paints containing a highly toxic biocide component were used to prevent growth on submerged surfaces, but these were banned because of the damaging effect they had on marine life. Shark skin provides a safe and effective anti-fouling strategy without the need for harmful chemicals, making Liedert's artificial shark skin research an area of great importance.

Liedert is presenting his work on the application of artificial shark skin at the Society for Experimental Biology Annual Meeting in Barcelona.

Source: Media release - Society for Experimental Biology